Combined wave and flow field visualization for investigation of short-wave/long-wave interaction
Short-waves modulated by long-waves have been investigated in the glass wave channel at Scripps Institution of Oceanography. Two series of mechanically generated wave trains of different amplitudes and wavelengths were produced consecutively in such a way that they superimpose 7.55 m from the wave maker. At this location, simultaneous records of wave slope images and the Lagrangian flow field were obtained, using an integrated two-camera setup, including particle-tracking and wave-slope instruments. With Digital Particle Tracking Velocimetry (DPTV), two-dimensional Eulerian and Lagrangian flow fields in an area of 17 by 20 cm2 in the water were calculated. From the wave slope image sequences phase speed, local frequency, and local wave number were obtained.